1. Field of the Invention
The present invention generally relates to methods and apparatus for circuit integration. More particularly, the present invention relates to methods and apparatus for circuit integration in Integrated Modular Avionics (IMA) cabinets which house printed circuit board modules in avionics systems in airplanes.
2. Description of the Related Art
In general, airplanes contain numerous electronic systems, such as avionics systems, cabin control systems, and energy maintenance systems. The electronic and computer components of these systems are typically disposed on printed circuit boards. In order to protect the printed circuit boards against electromagnetic interference (EMI), radio frequency interference (RFI), environmental contaminants, and vibrations, the printed circuit boards are typically contained in housings which are mounted on shelves in the airplane. The various signals and outputs transmitted and received by the printed circuit boards of an airplane's electronic system is integrated with an extensive circuit integration system. Various standards relating to the dimensions and configurations of the printed circuit boards, the housings, and the shelves used in an airplane are described by the ARINC standards, which are generally well known in the art and can be obtained from ARINC Incorporated of Annapolis, Md.
With reference to FIG. 1, a conventional IMA cabinet 100 houses a number of modules 102 containing printed circuit boards. The modules 102 of the conventional IMA cabinet 100 are interconnected to each other and connected to wiring harnesses of the airplane through a circuit interface located at the rear of the conventional IMA cabinet 100. The circuit interface, however, may take up considerable amount of space. For example, in one conventional IMA cabinet, the circuit interface may take up as much as 5 inches out of a total of 20 inches available for the entire cabinet. Additionally, the connections formed in the circuit interface of a conventional IMA cabinet are typically hard wired. Consequently, when the connections need to be reconfigured, repaired, or replaced, the connections formed in the circuit interface typically needs to be re-wired, which can be costly and time consuming.
With reference to FIG. 2, a conventional line replaceable unit (LRU) typically includes a housing 202 for enclosing the printed circuit boards. The LRU 200 also typically includes a circuit integration system for interconnecting the printed circuit boards. Similar to the conventional IMA cabinet 100, however, reconfiguring the circuit integration system for the LRU 200 is generally costly and time consuming because the entire LRU 200 typically needs to be removed from the shelf.